I'm pretty sure I read Spielberg was 2nd choice on Jedi after Kersh somewhere. but you're probably right. And I KNOW you're right on the second count
There's plenty to "bash" Lucas for without having to make stuff up. Like I said, it's in those biographies. There's plenty of ammo there if you want it, you dont' have to construct some soap opera villain and graft him onto Lucas body.